All too often, a person finds himself or herself with a mobile phone rendered inoperable by a totally depleted battery, and without any charging device. Also, just noting a low charge level in one's mobile device causes some people anxiety. Even one having a charger loses his or her mobility, if the cellular device has to be tethered to a wall outlet for an extended charging time period. Certainly, walking on the street provides one with no solution at all to a discharged battery.
Prior art devices such as telephone jackets which can be wrapped around a device such as the iPhone® and which house therein, an extra spare battery are known. Still, those devices are large and substantially increase the overall dimension of the cellular device being carried around.